if you're having unprotected sex and are surprised to get pregnant you must be a bit simple.
Quite. And if you're claiming a contraception 'accident', the most likely situations are either that you're lying or too daft to take your contraception properly. Actual contraception failures, when taking your contraception properly, can happen, but they are vanishingly rare. If it fails, it's almost always because you didn't do it properly.
Surely you know it’s not as clear cut as that. Totally straying from the subject of the sil and bil in the op, but do you know how many abortions are carried out every year in this country? Do you honestly think all of those pregnancies were planned? Or is it just that people who have unwanted pregnancies aren’t allowed to say “unplanned” in case it hurts someone’s feelings? They should have known better. They must be “simple” to fall pregnant by accident. Honestly, it’s a two way street when you’re banging your gavel demanding people BE MORE SENSITIVE snarl snarl.
How about this for a radical idea? Leave them to it. Maybe, as has been said on here, they’re feeling insecure about themselves and want to show off how hot / fertile they are. So what? It’s not an attack against someone struggling to conceive. Maybe it is a bit insensitive, but I’ve definitely heard a lot worse, and I think most people have said stupid things when they’re just starting out on an exciting new part of their lives.
When I got engaged for example, my cousin went a bit weird and I only realised later that she dearly wanted to marry her LTP, but he didn’t believe in marriage. She found the excitement around dh and me getting engaged, (honestly we really were quite understated and not at all “squee”, but there was a bit of excitement within the family), really hurtful.
We got married quite young and were one of the first couples in our friends and family to TTC dcs, so I only know from mumsnet the ‘things not to say’ to anyone about pregnancy, just in case they’re struggling to conceive. Otherwise I’d have put my foot in it by now I’m sure. Obviously the big no nos are just common sense “it’s not meant to be” etc, “just relax and it will happen”. That’s insensitive. But it’s not as bad as saying anyone who falls pregnant by accident is faking / simple / fucked up their contraception so it’s their fault. That’s actually deliberately unkind and totally lacking in empathy.